Transapical method of delivering prosthetic heart valve

ABSTRACT

A method of delivering a prosthetic heart valve to the aortic valve annulus while a patient&#39;s heart is beating. The method includes accessing the left ventricle through an intercostal incision and forming a puncture in the left ventricle. A guidewire is advanced into the left ventricle and through the native aortic valve. An introducer sheath is passed over the guidewire and into the left ventricle. A prosthetic heart valve is advanced over the guidewire and through the introducer sheath using a delivery catheter. After positioning the prosthetic heart valve in the native aortic valve, the prosthetic heart valve is radially expanded in the aortic valve annulus for replacing the function of the native aortic valve.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. application Ser. No.11/280,063, filed Nov. 16, 2005, now U.S. Pat. No. 8,764,820, which isincorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to methods and systems used to deliver aprosthetic valve to a heart. More specifically, the present inventionrelates to methods and apparatus for surgically replacing a heart valvewithout opening the chest cavity and with or without placing the patienton bypass, the latter being termed “off-pump.”

BACKGROUND OF THE INVENTION

Heart valve replacement may be indicated when there is a narrowing ofthe native heart valve, commonly referred to as stenosis, or when thenative valve leaks or regurgitates, such as when the leaflets arecalcified. When replacing the valve, the native valve may be excised andreplaced with either a biologic or a mechanical valve. Mechanical valvesrequire lifelong anticoagulant medication to prevent blood clotformation, and clicking of the valve often may be heard through thechest. Biologic tissue valves typically do not require such medication.Tissue valves may be obtained from cadavers or may be porcine or bovine,and are commonly attached to synthetic rings that are secured to thepatient's heart valve annulus.

Conventional heart valve surgery is an open-heart procedure conductedunder general anesthesia. An incision is made through the patient'ssternum (sternotomy), and the patient's heart is stopped while bloodflow is rerouted through a heart-lung “cardiopulmonary” bypass machine.Valve replacement surgery is a highly invasive operation withsignificant concomitant risks including bleeding, infection, stroke,heart attack, arrhythmia, renal failure, adverse reactions to theanesthesia medications, as well as sudden death. Fully 2-5% of patientsdie during surgery. Post-surgery, patients temporarily may be confuseddue to emboli and other factors associated with the heart-lung machine.The first 2-3 days following surgery are spent in an intensive care unitwhere heart functions can be closely monitored. The average hospitalstay is between 1 to 2 weeks, with several more weeks to months requiredfor complete recovery.

In recent years, advancements in “minimally-invasive” surgery andinterventional cardiology have encouraged some investigators to pursuepercutaneous replacement of the aortic heart valve. Percutaneous ValveTechnologies (“PVT”), formerly of Fort Lee, N.J. and now part of EdwardsLifesciences of Irvine, Calif., has developed a balloon-expandable stentintegrated with a bioprosthetic valve. The stent/valve device isdeployed across the native diseased valve to permanently hold the valveopen, thereby alleviating a need to excise the native valve. PVT'sdevice is designed for delivery in a cardiac catheterization laboratoryunder local anesthesia using fluoroscopic guidance, thereby avoidinggeneral anesthesia and open-heart surgery.

Other prior art minimally-invasive heart valves use self-expandingstents as anchors. In the percutaneous/endovascular aortic valvereplacement procedure, accurate placement of the prosthetic valverelative to the coronary ostia is critical. Though the proximal end ofthe stent is not released from the delivery system until accurateplacement is verified by fluoroscopy, the self-expanding stent may stilljump once released. It is therefore often difficult to know where theends of the stent will be with respect to the native valve andsurrounding structures.

U.S. Patent Publication No. 2002/0151970 to Garrison et al. describes atwo-piece device for replacement of the aortic valve that is adapted fordelivery through a patient's aorta. A stent is endovascularly placedacross the native valve, then a replacement valve is positioned withinthe lumen of the stent and connected thereto. By separating the stentand the valve during delivery, a so-called “two-stage” approach, theprofile of the delivery system can be reduced. Both the stent and aframe of the replacement valve may be balloon- or self-expandable.

Some researchers propose implanting prosthetic heart valves at theaortic annulus through a ventricular approach. For instance, ChristophH. Huber of the Brigham and Women's Hospital of Harvard Medical School,and others, have proposed a procedure in which a self-expanding valvestent is implanted at the aortic position using a direct-accesstransapical approach. (E.g., Huber, et al. Direct-access valvereplacement a novel approach for off-pump valve implantation usingvalved stents. J Am Coll Cardiol 2005; 46:366-70). The clinical studiesby Huber, et al. recommend use of the procedure only for animals withnormal, noncalcified leaflets. More recently, Bergheim in U.S. PatentPublication No. 2005/0240200 discloses another transapical approach inwhich either a balloon- or self-expanding valve may be implanted, andalso proposes removing or decalcifying stenotic valves.

In view of drawbacks associated with previously known techniques forreplacing a heart valve without open-heart surgery or cardiopulmonarybypass, i.e., minimally-invasive procedures, improved methods andapparatuses that are more robust and less invasive are needed.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide a heart valvedelivery system for delivery of a prosthetic (i.e., replacement) heartvalve to a native valve site without an open chest procedure. Thedelivery system includes a valve delivery catheter having a steerablesection to facilitate positioning of the valve.

In accordance with one aspect, the present invention provides anoff-pump, minimally-invasive surgical method of implanting a prostheticheart valve to an aortic valve annulus of a patient while the patient'sheart remains beating. The method includes providing aballoon-expandable prosthetic heart valve mounted over a balloon on adistal end of a balloon catheter. The physician creates a puncturethrough the ventricle wall at or near the apex of the left ventricle ofthe patient and inserts an introducer sheath through the puncture. Aballoon catheter passes through the introducer sheath into the leftventricle. The distal end of the balloon advances so that the prostheticheart valve is positioned within the aortic annulus. Finally, theballoon inflates to expand the prosthetic heart valve at the aorticannulus.

The method may also include placing a first line of purse-string suturesgenerally in a first circle in one direction defining a perimeter at ornear the apex of the left ventricle of the patient, and then placing asecond line of purse-string sutures generally in a circle concentric tothe first circle but in an opposite direction. The puncture is createdwithin the perimeter, and after the introducer sheath is insertedthrough the puncture, the purse-string sutures are cinched to create aseal therearound.

Desirably, the balloon catheter incorporates a steering mechanism, andthe method further includes steering the balloon catheter within theleft ventricle to facilitate positioning the prosthetic heart valvewithin the aortic annulus. The balloon catheter may also include adeflecting segment located just proximal to the balloon which bends soas to angle the balloon and prosthetic heart valve mounted thereon. Theballoon catheter may also have a pusher with a distal sleeve mountedover the deflecting segment and engaging a proximal end of the balloon.The method therefore includes using the pusher and sleeve to advance theballoon and prosthetic heart valve mounted thereon, and proximallydisplacing the pusher and sleeve with respect to the deflecting segmentprior to inflating the balloon. Desirably, the pusher and sleeve areproximally displaced before the deflecting segment bends.

The exemplary method may further include leaving the native aortic valveleaflets in place such that inflating the balloon expands the prostheticheart valve into contact therewith. Furthermore, a pre-dilation ballooncatheter may be inserted prior to the introducer sheath and a balloonthereon inflated to pre-dilate the aortic annulus. Alternatively, themethod may include expanding the prosthetic heart valve into contactwith a prosthetic heart valve that was previously implanted at theaortic annulus

Another off-pump, minimally-invasive surgical method of delivering aprosthetic heart valve to an aortic valve annulus of a patient while thepatient's heart remains beating includes providing an expandableprosthetic heart valve in an expanded state and a delivery catheterhaving a distal end. The heart valve is crimped to a contracted stateover the delivery catheter distal end. An intercostal access opening iscreated to expose the left ventricular apex of the patient, and apuncture formed at or near the apex of the left ventricle. An introducersheath inserts through the puncture, and the delivery catheter passesthrough the introducer sheath and into the left ventricle. The distalend of the delivery catheter is advanced and steered so that theprosthetic heart valve is properly positioned and oriented within theaortic annulus. Finally, the prosthetic heart valve expands at theaortic annulus into contact therewith.

The delivery catheter desirably includes a balloon on its distal end,and the prosthetic heart valve includes a balloon-expandable stent,wherein the step of expanding includes injecting fluid into the balloonto expand the prosthetic heart valve outward into contact with theaortic annulus. The native aortic valve leaflets may be left in placesuch that inflating the balloon expands the prosthetic heart valve intocontact therewith. Preferably, prior to inserting the introducer sheath,a pre-dilation balloon catheter having a balloon on a distal end isinserted through the puncture and inflated to pre-dilate the aorticannulus.

The present invention further encompasses a minimally-invasiveprosthetic heart valve delivery system, including an introducer sheathhaving a lumen therethrough of no greater than 24 French and a ballooncatheter having a balloon on a distal end, the balloon catheter furtherincluding a steering mechanism for deflecting the distal end. The systemincludes a balloon-expandable prosthetic heart valve crimped over theballoon, wherein the outer dimension of the balloon catheter with theprosthetic heart valve crimped thereon is small enough to pass throughthe introducer sheath lumen.

Desirably, the steering mechanism includes a deflecting segment on theballoon catheter located just proximal to the balloon. A deflection wiremay be attached to a distal end of the deflecting segment and extendthrough the balloon catheter to a proximal deflection handle. The systempreferably has a pusher with a distal sleeve sized to encompass thedeflecting segment and a proximal end of the balloon, the pusher beinglongitudinally movable with respect to the deflecting segment.

In one embodiment, the balloon catheter further includes inner and outerballoon inflation tubes attached to opposite ends of the balloon andarrange to concentrically slide with respect one another to alternatelyelongate and shorten the balloon. An inner tube handle displaces theinner balloon inflation tube. A balloon inflation connector throughwhich the inner balloon inflation tube passes attaches to a proximal endof the outer balloon inflation tube. A side port opens to a spacedefined within the balloon inflation connector, the side portfacilitating introduction of an inflation fluid into the space and intoa tubular space between the inner and outer balloon inflation tubes forinflating the balloon. A deflection handle through which the outerballoon inflation tube passes may be attached just distal to the ballooninflation connector. The outer balloon inflation tube includes a firstlumen for passage of the inner balloon inflation tube, and a secondlumen. A deflection wire connects to an actuator on the deflectionhandle and passes through the second lumen of the outer ballooninflation tube to a distal end of the balloon catheter.

The system is desirably relatively short, such that the balloon catheterhas a working length sized to fit into the introducer of no more thanabout 24 inches (61 cm). At the same time, the introducer preferably hasa total length of no more than about 13 inches (33 cm).

A further understanding of the nature and advantages of the presentinvention are set forth in the following description and claims,particularly when considered in conjunction with the accompanyingdrawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the present invention will become appreciatedas the same become better understood with reference to thespecification, claims, and appended drawings wherein:

FIG. 1 is a schematic frontal view of a patient showing the location ofan intercostal incision providing access to the apex of the leftventricle of the heart;

FIGS. 2A-2B are cross-sectional views through the left side of apatient's heart showing a procedure for dilating a calcified aorticannulus prior to implantation of a prosthetic heart valve in accordancewith the present invention;

FIGS. 3A-3E are cross-sectional views through the left side of apatient's heart showing several steps in a procedure for implanting aprosthetic heart valve in accordance with the present invention;

FIG. 4A is a side elevational view of an introducer used in theminimally-invasive heart valve implantation procedure of the presentinvention;

FIG. 4B is an exploded view of the introducer of FIG. 4A;

FIG. 5 is a perspective view of an exemplary balloon catheter forimplanting a prosthetic heart valve in accordance with the presentinvention;

FIG. 5A is a perspective view of a loader that provides an interfacebetween the introducer of FIG. 4A and the balloon catheter of FIG. 5;

FIG. 6A is an enlarged broken plan view of the balloon catheter of FIG.5;

FIG. 6B is an enlarged broken sectional view of the balloon catheter ofFIG. 5 taken along a vertical plane;

FIG. 7 is an enlarged broken portion of the proximal end of the ballooncatheter as seen in FIG. 6B;

FIG. 8 is an isolated side view of a tube segment having ananti-rotation block on one end that forms part of the balloon catheterof FIG. 5;

FIG. 9 is an isolated side view of a proximal end of an outer ballooninflation tube that forms part of the balloon catheter of FIG. 5;

FIG. 10 is an enlarged sectional view of a pusher handle that forms partof the balloon catheter as seen in FIG. 6B;

FIG. 11 is an enlarged sectional view of a distal deflecting segment ofthe balloon catheter as seen in FIG. 6B;

FIG. 12 is an enlarged sectional view of the distal balloon of theballoon catheter of the present invention in its expanded state;

FIG. 13 is an enlarged sectional view of a distal soft tip of theballoon catheter;

FIG. 14 is an enlarged elevational view of the distal end of the ballooncatheter showing the balloon in its deflated state partly encompassed bya pusher sleeve; and

FIG. 15 is an enlarged elevational view of the distal end of the ballooncatheter showing a protective sheath around the deflated balloon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The heart is a hollow muscular organ of a somewhat conical form; it liesbetween the lungs in the middle mediastinum and is enclosed in thepericardium. The heart rests obliquely in the chest behind the body ofthe sternum and adjoining parts of the rib cartilages, and projectsfarther into the left than into the right half of the thoracic cavity sothat about one-third is situated on the right and two-thirds on the leftof the median plane. The heart is subdivided by septa into right andleft halves, and a constriction subdivides each half of the organ intotwo cavities, the upper cavity being called the atrium, the lower theventricle. The heart therefore consists of four chambers; the right andleft atria, and right and left ventricles.

As seen in FIG. 1, the left ventricular apex LVA is directed downward,forward, and to the left (from the perspective of the patient). The apextypically lies behind the fifth left intercostal space (or between thefourth and fifth), 8 to 9 cm from the mid-sternal line, and about 4 cmbelow and 2 mm to the medial side of the left mammary papilla. Access tothe left ventricle may therefore be attained through an intercostalincision 20 as shown in dashed line, positioned over the fifth leftintercostal space. Such an approach is often termed a“mini-thoracotomy.”

In a preferred embodiment of the present invention, a surgeon implants aprosthetic heart valve over the existing native leaflets, which aretypically calcified. There are procedures and devices for removingcalcified leaflets, but the risks associated therewith, including arelease of calcific material into the bloodstream, are notinsignificant. Therefore, a heart valve replacement procedure thatinstalls the prosthetic heart valve directly over and contains thenative leaflets is preferred.

Those skilled in the art will recognize that it may be necessary topre-dilate the leaflets and annulus of the stenotic aortic valve beforedeploying a prosthetic valve within the aortic valve. FIGS. 2A and 2Bare two snapshots of a valvuloplasty procedure that may be initiallyperformed to compress the native aortic heart valve leaflets outwardagainst the sinuses and ascending aorta. As mentioned above, the nativeaortic valve leaflets may be substantially calcified, and thevalvuloplasty may be necessary to crack and otherwise force aparthardened tissue. Pre-dilation increases the flow area through the aorticvalve and creates an opening in the leaflets of sufficient size toreceive the prosthetic valve. Pre-dilatation is preferably achievedusing an expandable member, such as a dilatation balloon catheter. Oneexample of pre-dilation of a valve annulus is seen in U.S. Pat. No.6,908,481 to Cribier, issued Jun. 21, 2005 and expressly incorporated byreference herein.

FIG. 2A illustrates introduction of a guidewire 30 through an apicalpuncture 32 in the left ventricle LV. A distal tip 34 of the guidewire30 extends through the native aortic valve AV and into the ascendingaorta AA. The distal tip 34 may extend further over the aortic arch, asseen in FIG. 2B, but the minimum extension is across the aortic valveAV.

FIG. 2B illustrates a balloon catheter 40 having a dilatation balloon 42on a distal end passed over the guidewire 30 and through the apicalpuncture 32. It should be noted at this point that one or morepurse-string sutures 44 are threaded through the tissue of the leftventricular apex surrounding the puncture 32. These sutures 44 arepre-implanted prior to formation of the initial puncture. In a preferredembodiment, the surgeon places a first line of purse-string suturesgenerally in a first circle in one direction, and then places a secondline of purse-string sutures generally in a circle concentric to thefirst circle but in an opposite direction. The result is two concentriccircles of separate purse-string sutures 44 defining a periphery withinwhich the puncture is formed. The purse-string sutures 44 can thereforebe pulled to cinch the ventricular tissue around whatever object passesthrough the puncture. In particular, the purse-string sutures 44 aretightened around both the guidewire 30 and balloon catheter 40.Installing the separate lines of purse-string sutures 44 in oppositedirections helps prevent tearing of the ventricular tissue and providesa more uniform compression about whatever elongated object passesthrough the puncture.

As indicated in FIG. 2B, the dilatation balloon 42 expands radiallyoutward into contact with the native aortic valve leaflets. Withinformation concerning the size of the particular aortic valves, theballoon 42 is chosen so that it expands outward and nominally compressesthe aortic valve leaflets against the surrounding aortic walls. Thereare various means for assessing the size of the particular patient'saortic valve, including ultrasound, which will not be described herein.Suffice it to say that following the valvuloplasty procedure seen inFIG. 2B, the native aortic valve leaflets are compressed outward againstthe aortic wall and a substantially circular orifice results. Additionaldetails regarding pre-dilatation and valve replacement can be found inApplicant's U.S. Pat. No. 6,908,481, filed May 2, 2002, and expresslyincorporated by reference herein.

With reference now to FIGS. 3A-3E, a preferred method of deploying andimplanting a prosthetic heart valve of the present invention using atransapical approach will now be described in more detail. The devicesand methods disclosed herein are particularly well-suited for replacinga stenotic aortic valve, and as such that the pre-dilation procedureseen in FIGS. 2A-2B typically precedes the valve implantation so as tosmooth out the contours of the annulus and leaflets. It should be noted,however, that the procedure described herein may be performed withoutvalve pre-dilation.

Furthermore, the present procedure may be performed as a first timevalve implant or to supplement a previous implant. A relatively largeproportion of recipients of prosthetic heart valves are older, typicallyolder than 60. Over time, prosthetic heart valves have been known toshow reduced performance and even failure. Re-operating onseptuagenarians and even octogenarians is problematic. However, aminimally-invasive procedure such as disclosed herein eliminatesopen-heart surgery and potentially cardiopulmonary bypass, and istherefore more desirable for the aging patient. Therefore, the presentinvention contemplates transapical implantation of a prosthetic heartvalve over an existing prosthetic valve implant. In such a case, apre-dilation step is typically not necessary, though it is conceivable.

Prior to a discussion of the procedure itself, it should be noted that apreferred delivery system of the present invention will be described ingreater detail below with reference to FIGS. 4-15. The workings of thepresent delivery system may be more easily understood after anexplanation of the steps taken to ultimately implant the valve in theaortic annulus.

The prosthetic heart valve implantation procedure described herein maybe performed in conjunction with cardiopulmonary bypass, or without in aso-called off-pump procedure. The necessity for bypass depends on anumber of factors, including the patient's age, vulnerability to such aprocedure, and viability of the native leaflets. Ideally, theimplantation procedure is performed off-pump.

The surgeon or cardiologist first sizes the aortic valve using aphysical sizer, or echocardiography. The physician or operating roomstaff then crimps an expandable prosthetic valve 50 over the balloon 52of a balloon catheter 54 (some of the elements presently described canbe seen in the procedure drawings of FIGS. 3A-3E, while others can beseen in the system drawings of the FIGS. 4-15). The surgeon advances theballoon catheter 54 over a guidewire 60 (that might be the sameguidewire 30 used in a pre-dilation procedure), through an introducersheath 70 that has been inserted through the left ventricular apexpuncture 32.

The same purse-string sutures 44 that were used for the pre-dilationprocedure may also be used to seal the ventricular tissue around theintroducer sheath 70. In the absence of the pre-dilation procedure, thepurse-string sutures 44 are pre-implanted prior to formation of theinitial puncture. As before, the surgeon places a first line ofpurse-string sutures generally in a first circle in one direction, andthen places a second line of purse-string sutures generally in a circleconcentric to the first circle but in an opposite direction. The resultis two concentric circles of separate purse-string sutures 44 defining aperiphery within which the puncture is formed, and which seal around theintroducer sheath 70.

Furthermore, a dilator (not shown) that expands the inner diameter ofthe puncture 32 and rides over the guidewire 60 may be inserted prior tothe introducer sheath 70. Preferred dilator diameters range between 12and 22 French. The introducer sheath 70 comprises the distal end of anintroducer that will be described below. Introducer sheath diameters ofno greater than 24 French, and desirably 22 or 24 Fr are preferred.

FIG. 3A shows the introducer sheath 70 passing into the left ventriclethrough the puncture 32 and over the guidewire 60 that extends upwardthrough the calcified aortic valve AV. The surgeon locates a distal tip72 of the introducer sheath 70 just to the inflow side of the aorticvalve AV, as seen in FIG. 3A. At this point, it should be understood bythose of skill in the art that the position of the introducer sheath 70relative to the aortic valve AV, as well as the position of otherelements of the system, is monitored using radiopaque markers andfluoroscopy, or using other imaging systems such as transesophagealecho, transthoracic echo, intravascular ultrasound imaging (IVUS), or aninjectable dye that is radiopaque.

FIG. 3B shows the advancement of the balloon catheter 54 over theguidewire 60 and through the introducer sheath 70. Ultimately, as seenin FIG. 3C, the prosthetic heart valve 50 is located at the aorticannulus and between the native aortic leaflets. FIG. 3C also illustratesretraction of the introducer sheath 70 from its more forward position inFIG. 3B. Radiopaque markers may be provided on the distal end of theintroducer sheath 72 more accurately determine its position relative tothe valve 50 and balloon 52.

Again, the precise positioning of the prosthetic heart valve 50 may beaccomplished by locating radiopaque markers on its distal and proximalends. Desirably, the surgeon can adjust the position of the valve 50 byactuating a steering or deflecting mechanism within the balloon catheter54, as will be described below. Furthermore, the rotational orientationof the valve 50 can be adjusted relative to the cusps and commissures ofthe native aortic valve by twisting the balloon catheter 54 from itsproximal end and observing specific markers on the valve (or ballooncatheter) under fluoroscopy. One of the coronary ostia 80 opening intoone of the sinuses of the ascending aorta is shown, and those of skillin the art will understand that it is important not to occlude the twocoronary ostia with the prosthetic valve 50. It should also be notedthat although the native leaflets of the aortic valve AV are showncoapting in FIG. 3A, and being flexibly displaced by the ballooncatheter 54 in FIGS. 3B and 3C, they may actually be compressed furtheroutward against the aortic annulus from a pre-dilation procedure.

FIG. 3C shows the prosthetic heart valve 50 in its contracted orunexpanded state crimped around the balloon 52. When the surgeon issatisfied of the proper positioning and rotational orientation of thevalve 50, the balloon 52 is expanded as seen in FIG. 3D. Proper sizemeasurement of the native aortic valve AV enables the surgeon to selectan optimum-sized valve 50 such that it expands outward into good contactwith the aortic annulus. The term “good contact” implies sufficientcontact to ensure that the prosthetic heart valve 50 does not migrateafter implant. Excessive expansion of the valve, however, may damagesurrounding tissue or interfere with the performance of adjacent valves.

A number of devices are available to assist in anchoring the prostheticvalve 50 into the aortic annulus, such as barbs and the like. Apreferred configuration of prosthetic heart valve 50 for use with thepresent invention is disclosed in co-pending U.S. Pat. No. 7,276,078,filed Jun. 30, 2004, which disclosure is expressly incorporated hereinby reference. Of course, the valve 50 can take a variety of differentforms but generally comprises an expandable stent portion that supportsa valve structure. The stent portion has sufficient radial strength tohold the valve at the treatment site and resist recoil of the stenoticvalve leaflets. Additional details regarding preferred balloonexpandable valve embodiments can be found in U.S. Pat. Nos. 6,730,118and 6,893,460, both of which are expressly incorporated herein byreference. The preferred prosthetic heart valve 50 includes sufficientirregularity on its outer surface such that it may be anchored in theaortic annulus without the use of barbs or other tissue piercingstructure.

Once the valve 50 is properly implanted, as seen in FIG. 3D, the balloon52 is deflated, and the entire delivery system including the ballooncatheter 54 is withdrawn over the guidewire 60. The guidewire 60 is thenwithdrawn, followed by the introducer sheath 70. Ultimately, thepurse-string sutures 44 previously described are cinched tight and tiedto close the puncture 32, as seen in FIG. 3E

It is important to recognize that the heart valve delivery system of thepresent invention is particularly well-suited for the antegrade, leftventricular apex, “transapical,” approach. More particularly, themini-thoracotomy approach requires relatively short instruments.Therefore, the portion of the introducer sheath 70 that extends into thebody is desirably no more than about 8 inches (20 cm) long, and thelength of the balloon catheter 54 that may extend into the introducersheath 70, i.e., the “working length,” is desirably no more than about24 inches (61 cm). Further specifics on the relatively short length ofthe balloon catheter 54 and introducer sheath 70 will be provided below.The short length of the prosthetic heart valve delivery system describedherein is also well-suited for other anatomical approaches, includingthrough the carotid or subclavian arteries. The short length of thesystem is desirable because it enhances controllability and steerabilityof the distal end, relative to longer systems, which helps improveaccuracy and reduced time for valve positioning.

The delivery system of the present invention essentially comprises anintroducer 100, the balloon catheter 54, and attendant couplers andoperating structures, including a loader 140 between the introducer andballoon catheter as seen in FIG. 5A. The introducer 100 is illustratedin FIGS. 4A and 4B, while the balloon catheter 54 and loader 140 areshown in FIGS. 5-15. It should be noted that the delivery system issimilar to another system used to percutaneously implant a prostheticaortic valve, which is disclosed in co-pending U.S. Pat. No. 7,780,723,filed Jun. 13, 2005, and expressly incorporated herein by reference. Thepresent system differs in several aspects that make it more suitable fora transapical approach, although some features are common.

As seen in FIGS. 4A and 4B, the introducer 100 comprises theaforementioned distal sheath 70 coupled to an introducer housing 102containing a series of valves. The exploded view of FIG. 4B shows an endcap 104 detached from the introducer housing 102. The end cap 104includes a flanged nipple 105 for mating with the loader 140, as will beexplained below. The end cap 104 threads or otherwise attaches to thehousing 102 and retains therein, in series from proximal to distal, across-slit valve 106, a spacer 108, a disk valve 110, and a duck-billvalve 112. These three valves function to provide a seal when noinstruments pass through the introducer 100, and when several differentsizes of instruments pass therethrough. For example, the valves sealaround both the guidewire 60 and the balloon catheter 54 as previouslyshown. The introducer sheath 70 extends into the body vessel, with theintroducer housing 102 located outside the body vessel. In a preferredembodiment, the introducer sheath 70 possesses an external hydrophiliccoating and has a length of about 8 inches so that it may extend throughthe access incision 20 (see FIG. 1), into the left ventricle and reachthe aortic annulus.

The introducer sheath 70 attaches to the housing 102 via an intermediatesection of tubing 120. The tubing 120 is desirably size slightly largerthan the sheath 70 such that it can be shrunk around a proximal endthereof. The proximal end of the tubing 120 includes a sealing flange122 that mates with a distal nipple 124 extending from the housing 102.Preferably adhesive is used between these two mating sections. A nuthousing 126 rides over the tubing 120 and couples to threading 128provided on the housing 102 just proximal to the nipple 124. In thisway, the various components can be manufactured (typically molded orextruded) separately and easily coupled together during assembly.

A side port tube 130 extends at an angle away from the introducerhousing 102 and terminates in a three-way stopcock 132. This permits theuser to infuse medicaments or other fluids through the lumen of theintroducer 100 even if devices such as the balloon catheter 54 arepresent therein.

FIG. 5 illustrates in perspective the balloon catheter 54, whichcomprises an assembly of interrelated components commencing on aproximal end with a luer fitting 142 and terminating at a distal end ina soft tip 144. The loader 140 shown in perspective in FIG. 5A will bedescribed in more detail below and provides a coupling between theballoon catheter 54 and the above-described introducer 100. The ballooncatheter 54 is also shown in plan, sectional, and isolated views inFIGS. 6-15 and comprises, from proximal to distal, an inner tube handle150 having the luer fitting 142, a balloon inflation connector 152, adeflection handle 154, an outer balloon inflation tube 156, a pusherhandle 158, a pusher body 160, a pusher sleeve 162, a deflecting segment164, and an expandable balloon 52 located just proximal to the soft tip144. An internally threaded loader cap 170 fits over the pusher body 160and couples to the loader 140.

Prior to a detailed description of the exemplary balloon catheter 54,its interaction with the introducer 100 via the loader 140 will beexplained. The loader 140 has a tube-shaped body with exterior threading172 at a proximal end for connection with internal threading on theloader cap 170, and a slightly externally tapered distal nose 174 thatfits within the introducer 100. The loader 140 includes a pair ofattached cantilevered fingers 176 extending parallel thereto withinternally facing snap ridges 178 for securing the loader 140 to theintroducer 100. An annular loader seal 180, seen better in FIGS. 6A and6B, is positioned within the loader cap 170. The annular loader seal 180comprises a pair of annular washers 182, preferably nylon, that sandwichtherebetween an annular resilient seal 184, preferably silicone.

The loader 140 facilitates introduction of the balloon catheter 54 intothe introducer 100. As described above, the introducer housing 102contains the series of valves 106, 110, 112 that in aggregate provide aneffective fluid seal against egress of blood through the introducer 100in the absence or presence of different sized medical implements. Thedistal nose 174 of the loader 140 extends through the introducer housing102 and through these valves 106, 110, 112 to hold them open and providea smooth internal lumen which matches the size of the lumen of theintroducer sheath 70. In this way, the somewhat irregular contours ofthe balloon catheter 54 having a prosthetic valve 50 crimped around theballoon 52 may smoothly pass into the introducer sheath 70.

Prior to balloon expansion as seen in FIG. 5, the loader 140 couplesover the distal extent of the balloon catheter 54 and is displacedproximally until it can be coupled with the loader cap 170. Screwing theloader cap 170 onto the external threats 172 of the loader 140 axiallycompresses the loader seal 180 to provide a fluid tight fit and lock theloader 140 with respect to the balloon catheter 54. At this point, thedistal extremity of the balloon catheter 54, including the balloon 160,is located within the tubular body of the loader 140. The distal nose174 inserts into the introducer housing 102 and the cantilevered loaderfingers 176 mate with the flanged nipple 105 of the end cap 104 (FIG.4A). The balloon catheter 54 is thus coupled to the introducer 100. Theloader cap 170 is then loosened, permitting axial displacement of theballoon catheter 54 with respect to the loader 140. Sliding the entireballoon catheter 54 distally permits the irregular contours of thedistal extremity thereof to pass safely across the valves 106, 110, 112and into the introducer sheath 70. The loader 140 remains coupled to theintroducer 100 during the valve implant procedure, and the loader cap170 can be re-tightened if necessary to secure the relative positions ofthe balloon catheter 54 and introducer 100.

The various components of the balloon catheter 54 will now be describedwith expect to FIG. 5, and the more detailed views of FIGS. 6-15. Withreference to the FIGS. 6A and 6B, the balloon inflation connector 152comprises a main body 186 having a proximal section 188 and a distalsection 190. Extending longitudinally through the proximal section 188is a first bore 192, while extending longitudinally through the distalsection 190 is a second bore 194 which communicates with the first bore192. The first bore 192 has a non-circular cross-sectional configurationfor reasons which will be discussed in more detail below. Disposed onthe distal end of the distal section 190 is a distal connector nut 196,while disposed on the proximal end of the proximal section 188 is aninflation cap 198 that retains an inflation seal 199 within theinflation connector 152. The second bore 194 widens at its distal endinto an enlarged opening that receives a connector nipple 200 alsoattached within the deflection handle 154.

The balloon catheter 54 of the present invention desirably incorporatesrelatively sliding concentric inner and outer balloon inflation tubesthat attach to opposite ends of the balloon 52. Without going into greatdetail, the concentric tubes permit the balloon 52 to be shortened orlengthened depending on the relative movement therebetween. Thisprovides the ability to axially extend the balloon 52 after it has beendeflated so that its radial profile is reduced and it may be easilyremoved from the surrounding structures, anatomical or otherwise.Inflation fluid, preferably saline, passes in a tubular space providedbetween the concentric balloons. In the present invention, the balloon52 expands the prosthetic heart valve 52 to implant it in the annulus,after which the balloon is deflated and axially elongated before beingremoved from within the valve. A detailed discussion of the structureand function of this concentric tube configuration may be found in U.S.Pat. No. 5,968,068, the disclosure of which is expressly incorporated byreference herein.

An inner balloon inflation tube 210 is seen at its proximal endextending into the inner tube handle 150 in FIG. 6B, and also in theenlarged view of FIG. 7. The tube 210 fixes concentrically within a tubesegment 212 (seen isolated in FIG. 8), a proximal end of which, in turn,is fixed within a bore of the tube handle 150. An anti-rotation block214 fixed on the distal end of the tube segment 212 axially slideswithin the first bore 192 of the inflation connector body 186. The firstbore 192 and anti-rotation block 214 are non-circular in radialcross-section to prevent relative rotation therebetween. Preferably,these elements are square. This also prevents rotation between the innertube 210 and the inflation connector 152.

The proximal end of the outer balloon inflation tube 156 is seen inFIGS. 6B and 7 extending into the deflection handle 154 to be fixedlyreceived within the connector nipple 200. As seen in isolation in FIG.9, the outer balloon inflation tube 156 has a larger cross-section atthe distal end of the deflection handle 154 than it does at itstermination in the connector nipple 200. An outer portion of the tube156 fastens within a connector at the distal end of the hollow body 230of the deflection handle 154, while a smaller diameter fluid-carryingtube 215 extends through the deflection handle to the connector nipple200. The fluid-carrying tube 215 receives the inner balloon inflationtube 210, while another lumen defined within the outer balloon inflationtube 156 receives a deflection wire, as described below. The connectornipple 200 is fixed (e.g., adhered or similarly secured) with respect toboth the inflation connector 152 and deflection handle 154, renderingthese two elements essentially contiguous. It can therefore be seen, asin FIG. 6B, that displacement of the inner tube handle 150 with respectto the inflation connector 152 also displaces the inner tube 210 withrespect to the outer tube 156.

A Y-port 216 in the distal section 190 of the balloon inflationconnector main body 186 leads to a side tube and a stop-cock valve 218.The valve 218 provides a connection point for a source of saline forinflating the balloon 52. The second bore 194 in the main body 186 isopen to the first bore 192 which is, in turn, sealed at the inflationcap 198 on the proximal end of the inflation connector 152. Saline thuspasses in a distal direction past the connector nipple 200 through atubular space outside of the inner tube 210 and inside thefluid-carrying tube 215 of the outer tube 156. The concentric spacebetween the tubes 210, 215 provides a pathway for the saline into thedistal balloon 152.

Still with reference to FIG. 7, the inner tube handle 150 features apair of opposed cantilevered clips 220 that serve to temporarily attachthe tube handle to the inflation cap 198 on the proximal end of theinflation connector 152. By squeezing the proximal ends of the clips 220their distal ends open up and the inner tube handle 150 can be displacedin a proximal direction with respect to the inflation cap 198. After ashort distance of travel, typically between 1-2 cm, the distal ends ofthe clips 220 are located over a short flanged nipple 222 on theinflation cap 198 and can be released so that inwardly facing teeth onthe clips 220 engaged the flange. This operation displaces the innerballoon inflation tube 210 with respect to the outer balloon inflationtube 156, which in turn causes the opposite axial ends of the balloon 52to move apart. As mentioned above, this movement facilitates thereduction in profile of the deflated balloon. The interaction betweenthe teeth on the clips 220 and the flanged nipple 222 holds the relativeposition of the outer and inner tubes 156, 210 such that the balloon 52remains locked in its extended configuration for ease of removal.

The luer fitting 142 on the proximal end of the inner tube handle 150provides an entry point for injection of radiographic contrast medium.The luer fitting 142 opens to the lumen of the inner balloon inflationtube 210 which continues to the distal end of the balloon catheter 54where an egress port is provided. Contrast medium is useful to check forparavalvular leaks after the prosthetic valve is implanted.

With reference both to FIGS. 6B and 7, the deflection handle 154includes a generally hollow body 230 having an axial slot on one sidethat receives a slider 232, seen in FIG. 6A. The hollow body 230 definesa series of partial external circumferential ribs 234 opposite theslider 232 to facilitate gripping by the user. Although it is notreadily apparent from the cross-sectional view of FIG. 7, the slider 232attaches within the handle body 230 to a deflection wire 236 that passesinto one of the lumens provided within the larger portion of the outerballoon inflation tube 156. The enlarged view of FIG. 11 illustrates adistal end of the outer tube 156 and shows the deflection wire 236extending therefrom. Specifics of the attachment of the deflection wire236 to the distal end of the balloon catheter 54 will be given below.Suffice it to say that axial movement of the slider 232 translates intoaxial movement of the deflection wire 236.

With reference to FIGS. 6A-6B and 10, the pusher handle 158 comprises atubular body 240 having a longitudinally extending lumen 242 thatslidingly receives the outer tube 156 therethrough. A pair of connectornuts 244, 246 couple to respective proximal and distal ends of the body240, and in particular mate with external threads provided thereon. Atubular side arm 248 extends angularly from the body 240 andcommunicates with the lumen 242 therein. The proximal end of the pusherbody 160 desirably bonds within the distal end of the body 240, and alumen defined within the pusher body fluidly communicates with the lumen242 of the pusher handle body 240. Since the side arm 248 opens into thelumen 242, which surrounds the outer balloon inflation tube 156, fluidintroduced through the side arm enters the concentric space between theouter tube 156 and the pusher body 160. The side arm 248 provides amulti-function port for introduction of angiography fluid, heparin, orother such therapeutic substances. The proximal connector nut 244axially compresses a sealing member 252 to both secure the pusher handle158 to the outer balloon inflation tube 156, and provide a fluid sealtherebetween.

Reference now to FIG. 11, the pusher body 160 attaches on its distal endto a flared pusher sleeve 162. Although shown separated, the pushersleeve 162 surrounds the deflecting segment 164 and a proximal portionof the balloon 52 during passage through the introducer sheath 70. Thedeflecting segment 164 generally comprises an outer flexible cover 262surrounding an inner coil spring 264. The pusher body 160 and pushersleeve 162 facilitate advancement of the deflecting segment 164 andattached balloon 52 having the valve 50 crimped thereon through theintroducer sheath 70. Proximal retraction of the pusher body 160relative to the outer balloon inflation tube 156 frees the deflectingsegment 164 and the balloon 52. As seen best in FIG. 5, the pusherhandle 158 may slide proximally over the balloon inflation tube 156 byloosening the proximal connector nut 244, thus pulling the pusher body160 back with respect to the tube 156.

As mentioned above, the deflection handle 154 supports the slider 232(FIG. 6A) which is connected to the deflection wire 236, seen extendingthrough the deflecting segment 164 in FIG. 11. In this regard, thedeflection wire 236 extends from the deflection handle 154 along one ofthe lumens in the outer balloon inflation tube 156. The tube 156terminates just within the flexible cover 262 of the deflecting segment164, and more particularly is fastened within a rigid proximal tubesegment 274 to which the flexible cover 262 also attaches at 260, suchas with adhesives. The coil spring 264 desirably includes tightly woundsections 270, 272 at both ends, a proximal one of which is securedwithin the distal end of the tube 156. The deflection wire 236 exits theouter tube 156 and passes around the outside of the coil spring 264,finally fastening to a distal tube segment 276 of the deflecting segment164. The tube segment 276 provides a rigid anchor for the flexible cover262, coil spring 264, and the proximal end of the balloon 52.

Tension in the deflection wire 236 pulls on one side of the distal tubesegment 276 which causes the distal end of the deflecting segment 164 tobend in that direction. Of course by rotating the entire ballooncatheter 54 about its axis the deflecting segment 164 may be steered inany direction. The coil spring 264 provides both flexibility andresiliency such that release of tension on the deflection wire 236permits the deflecting segment 164 to return to a straight orientation.Because the balloon 52 attaches to the distal end of the deflectingsegment 164, the prosthetic heart valve 50 crimped thereon may beoriented precisely within the native annulus.

With reference again to FIGS. 6A and 6B and 12, the balloon 52 includesa first cone portion 288, a main cylindrical portion 290, and a secondcone portion 292. The prosthetic heart valve 50 desirably crimps aroundthe main cylindrical portion 290, such as shown in phantom in FIG. 12.The balloon 52 can be formed of nylon, and is rated at a burst pressureof 6-8 atm. In preferred embodiments, the expanded diameter of theballoon ranges from about 20 to 28 mm, the particular size depending onthe size of the heart valve 50 being implanted.

The inner balloon inflation tube 210 passes through the balloon 52 andterminates at a distal end that is capped by the aforementioned soft tip144, best seen in FIG. 13. The soft tip 144 facilitates introduction ofthe balloon catheter 54 and reduces trauma to surrounding tissue. Thisis particularly important in the preferred procedure of the presentinvention where the catheter enters the apex of the left ventricle andtravels through the aortic valve into the ascending aorta. As was seenin FIG. 3D, the distal tip of the catheter may extend far enough toenter the aortic arch, and the soft tip 144 thus prevents rupture orother abrasion to the surrounding vascular tissue. FIG. 13 alsoillustrates the open distal end of the inner tube 210 and soft tip 144through which radiographic contrast medium may be injected to test valvesufficiency after implant.

FIG. 14 is an elevational view of the distal end of the balloon catheter54 showing the balloon 52 deflated and its proximal end encompassed bythe pusher sleeve 162. This view also shows a series of inflation holes298 provided in the inner tube 210 through which saline passes toinflate the balloon 52.

FIG. 15 shows the distal end of the balloon catheter 54 as it isdelivered in its packaging. Specifically, a protective sheath 300 isprovided surrounding the balloon 52 which is removed in the operatingroom prior to the implantation procedure.

In use, the present invention provides a novel and effective way forimplanting a prosthetic heart valve 50 in the aortic annulus. The stepsof the procedure have been described above with respect to FIGS. 1-3, atleast as far as the final implantation steps. A description of theadvantageous use of the exemplary balloon catheter 54 in performing theentire procedure will now be provided.

First, as mentioned above, the physician determines the size of thepatient's annulus. This can be done physically by creating the incision20 and puncture 32 in the left ventricular apex, and inserting a sizingtool into the aortic annulus. However, the puncture 32 may not be largeenough to pass a conventional sizer, and an alternative technique suchas echocardiography or other such imaging system may be utilized.

Next, the balloon catheter 54, introducer 100, loader 140, andprosthetic heart valve 50 are selected, and prepared for use by removingthem from any packaging and rinsing or sterilizing as needed. Apre-dilation step as described above with respect to FIGS. 2A-2B may beperformed to enlarge or crack existing calcification in the aorticannulus.

The process of crimping the prosthetic heart valve 50 over the balloon52 may be accomplished in a number of ways, and there are suitabledevices on the market for crimping balloon-expanding stents overballoons. In a preferred embodiment, a device having a compressingmechanism that works like the aperture iris of a camera is utilized. Insuch a device, multiple continuous segments around the periphery of theprosthetic heart valve 50 close separately but in concert so thatuniform inward pressure is exerted on the heart valve. The devicestypically operate manually.

Subsequently, the aforementioned pusher body 160 and flared sleeve 162are advanced distally over the proximal end of the balloon 52, such asseen in FIG. 14. The pusher handle 158 is secured in this position byscrewing tight the connector nut 244. The loader 140 is then securedover the distal end of the balloon catheter 54, including the assemblyof the deflecting segment 164, balloon 52 and prosthetic valve 50. Theloader 140 fastens in this position through engagement of the loader cap170 with the proximal threads 172 of the loader body.

At this point, or at the same time as balloon catheter preparation, theintroducer 100 is positioned within the left ventricle as seen in FIG.3A. Again, the purse-string sutures 44 maintain a fluid tight sealaround the introducer sheath 70. During the entire procedure the heartmay continue beating. The physician inserts the distal nose 174 of theloader 140 into the proximal opening of the introducer housing 102 andbottoms the loader out such that the cantilevered fingers 176 engage theflanged nipple 105 of the introducer. At this point, the ballooncatheter 54 is ready for introduction in the body.

Loosening the loader cap 170 permits distal advancement of the ballooncatheter 54 with respect to the loader 140 and introducer 100. Thephysician then retracts the pusher sleeve 162 from the deflectingsegment 164 and the proximal portion of the balloon 52 by loosening theconnector nut 244 (FIG. 10) and pulling back the pusher handle 158 overthe outer balloon inflation tube 156. The physician advances thecatheter 54 until it reaches the position shown in FIG. 3C, which alsoinvolves retraction of the introducer sheath 70. The entire operation isvisualized using radiographic markers and fluoroscopy, and the precisepositioning of the balloon 52 and prosthetic valve 50 mounted thereon isaccomplished by axial movement and rotation of the catheter 54 coupledwith angular changes of the deflecting segment 164. Specifically, as theprosthetic valve 54 advances it is aligned as much as possible along theflow axis of the native aortic valve AV by gross movement of thecatheter 54 and slight changes in its angular orientation by tensioningthe deflecting wire 236 with the slider 232 (FIG. 6A).

Ultimately, the valve 50 is positioned correctly as in FIG. 3C takingcare that the valve 50 is not liable to block either of the coronaryostia 80 when expanded. Saline is then injected through the stopcock 218(FIG. 6B) which passes through the Y-port 216 and into the tubular spacebetween the outer and inner balloon inflation tubes 156, 210. Salinecontinues distally through fluid passages in the balloon catheter 54 andfills the balloon 52. The balloon 52 is of a type that has a maximumexpanded diameter which has previously been selected to properly expandthe prosthetic heart valve 52 to its optimum diameter in contact withthe surrounding aortic valve AV, and calcified leaflets if they remainin place. The step is illustrated in FIG. 3D.

Subsequently, saline pressure is reduced within the balloon 52permitting it to deflate. The deflation may be assisted by axiallyextending the opposite ends of the balloon 52 by moving the inner tubehandle 150 distally toward the inflation handle 152 (see FIG. 6B).Radiographic contrast medium may be injected from the proximal lure 142of the balloon catheter 54 to egress through the distal soft tip 144 andtest the efficacy of the just-implanted prosthetic valve 50. If thevalve is properly functioning, the balloon catheter 54 is withdrawn intothe introducer sheath 70, which is removed from the puncture 32. Thepurse-string sutures 44 are closed up to seal the puncture 32.

Once again, the delivery system described herein is particularlywell-suited for an antegrade, transapical approach, partly because ofits relatively short length. With reference to FIG. 4A, the entirelength of the introducer 100 is approximately 13 inches (33 cm), whilethe length of the sheath 70 that may extend within the body is about 8inches. The portion of the balloon catheter 54 that extends into theintroducer 100 (that is, the portion of the balloon catheter from thedistal soft tip 144 to approximately the deflection handle 154) is nomore than about 24 inches (61 cm), which permits about 11 inches (28 cm)of the balloon catheter to extend beyond the introducer distal tip 72(see FIG. 4). It should be noted that the relatively short length of thedelivery system is unsuited for a longer, more circuitous approachthrough the peripheral vasculature, such as shown in co-pending U.S.Pat. No. 7,780,723. Also, the steering mechanism is provided on theballoon catheter 54 itself, rather than on a secondary catheter used forguiding the balloon catheter, as is done in U.S. Pat. No. 7,780,723. Theshort length of the balloon catheter and the ability to directlymanipulate it greatly enhances successful positioning of the prostheticheart in the aortic annulus.

While the invention has been described in its preferred embodiments, itis to be understood that the words which have been used are words ofdescription and not of limitation. Therefore, changes may be made withinthe appended claims without departing from the true scope of theinvention.

What is claimed is:
 1. A method of implanting a prosthetic heart valvein an aortic valve annulus of a patient while the patient's heartremains beating, comprising: accessing a left ventricle through anintercostal incision; forming a puncture in the left ventricle;introducing a guidewire through the puncture and into the leftventricle; advancing the guidewire through a native aortic valve;passing an introducer sheath over the guidewire and through the punctureinto the left ventricle, the introducer sheath having a lumen extendingtherethrough, the introducer sheath including a proximal housingcontaining a valve assembly for preventing bleeding from the lumen;inserting a valve delivery device over the guidewire, through the valveassembly and through the lumen of the introducer sheath, the valvedelivery device having a prosthetic heart valve mounted thereon adeflecting segment located just proximal to the prosthetic heart valveand a pusher having a distal sleeve mounted over the deflecting segment;advancing the valve delivery device over the guidewire until theprosthetic heart valve is located in the aortic valve annulus; using thepusher and sleeve to advance the prosthetic heart valve; proximallydisplacing the pusher and sleeve with respect to the deflecting segmentand then bending the deflecting segment from a proximal handle tofacilitate positioning the prosthetic heart valve in the aortic valveannulus; and then expanding the prosthetic heart valve in the aorticvalve annulus, wherein the step of expanding the prosthetic heart valvein the aortic valve annulus comprises expanding the prosthetic heartvalve in a prosthetic heart valve previously implanted within the nativeaortic valve annulus.
 2. The method of claim 1, further comprisingplacing a purse-string suture generally in a circle defining a perimeterthrough the tissue of the left ventricle, and forming the puncturewithin the perimeter of the purse-string suture.
 3. The method of claim1, further comprising the steps of: passing a balloon catheter having adilatation balloon on a distal end over the guidewire and through thepuncture in the left ventricle; advancing the dilatation balloon to aposition in the native aortic valve; and radially expanding thedilatation balloon, thereby compressing leaflets of the native aorticvalve against the previously implanted prosthetic heart valve.
 4. Themethod of claim 1, wherein the valve delivery device comprises a ballooncatheter with a balloon on its distal end and wherein the balloon isinflated to expand the prosthetic heart valve in the aortic valveannulus.
 5. The method of claim 1, wherein the valve delivery deviceincludes a steering mechanism for bending the deflecting segmentcontrolled from the proximal handle thereof, and further comprising:steering the valve delivery device from the proximal handle with thesteering mechanism within the left ventricle to facilitate positioningthe prosthetic heart valve in the aortic valve annulus.
 6. The method ofclaim 1, further including the steps of: prior to inserting the valvedelivery device through the valve assembly, attaching a loader to theproximal housing for holding the valve assembly open while the valvedelivery device is inserted through the introducer sheath.
 7. Anoff-pump method of implanting a prosthetic heart valve in an aorticvalve annulus of a patient while the patient's heart is beating,comprising: threading one or more purse-string sutures in a circularpattern through tissue of the left ventricle; forming a puncture in thewall of the left ventricle within the circular pattern of the one ormore purse-string sutures; introducing a guidewire through the punctureand into the left ventricle; advancing the guidewire through an aorticvalve annulus: while maintaining tension on the one or more purse-stringsutures, advancing a dilator over the guidewire and through the punctureinto the left ventricle; while maintaining tension on the one or morepurse-string sutures, passing an introducer sheath over the dilator,through the puncture and into the left ventricle, the introducer sheathhaving a lumen extending therethrough; removing the dilator from withinthe introducer sheath; advancing a valve delivery device over theguidewire, through the valve assembly of an introducer housing andthrough the lumen of the introducer sheath, the valve delivery devicehaving a prosthetic heart valve mounted thereon a deflecting segmentlocated just proximal to the prosthetic heart valve and a pusher havinga distal sleeve mounted over the deflecting segment; advancing the valvedelivery device and prosthetic heart valve over the guidewire until theprosthetic heart valve is positioned in the aortic valve annulus; usingthe pusher and sleeve to advance the prosthetic heart valve; proximallydisplacing the pusher and sleeve with respect to the deflecting segmentand then bending the deflecting segment from a proximal handle tofacilitate positioning the prosthetic heart valve in the aortic valveannulus; and then expanding the prosthetic heart valve in the aorticvalve annulus, wherein the step of expanding the prosthetic heart valvein the aortic valve annulus comprises expanding the heart valve in aprosthetic heart valve previously implanted in the aortic valve annulus.8. The method of claim 7, wherein the step of threading one or morepurse-string sutures comprises placing a first line of purse-stringsutures generally in a first circle in one direction defining thecircular pattern through the tissue of the left ventricle, and thenplacing a second line of purse-string sutures generally in a circularpattern concentric to the first circular pattern but in an oppositedirection.
 9. The method of claim 7, further comprising the steps of:passing a balloon catheter having a dilatation balloon on a distal endover the guidewire and through the puncture in the wall of the leftventricle; advancing the dilatation balloon to a position in the nativeaortic valve; and radially expanding the dilatation balloon, therebycompressing leaflets of the native aortic valve against the previouslyimplanted prosthetic heart valve.
 10. The method of claim 7, wherein thevalve delivery device comprises a balloon catheter having a balloonpositioned along a distal end portion and wherein the balloon isinflated to expand the prosthetic heart valve in the aortic valveannulus.
 11. The method of claim 7, wherein the valve delivery deviceincludes a steering mechanism for bending the deflecting segmentcontrolled from the proximal handle thereof, and further comprising:steering the valve delivery device from the proximal handle with thesteering mechanism within the left ventricle to facilitate positioningthe prosthetic heart valve in the aortic valve annulus.
 12. The methodof claim 7, further including the steps of: prior to inserting the valvedelivery device through the valve assembly, attaching a loader to theproximal housing for holding the valve assembly open while the valvedelivery device is inserted through the introducer sheath.
 13. Anoff-pump method of implanting a prosthetic heart valve in an aorticvalve annulus of a patient while the patient's heart is beating,comprising: providing a delivery catheter having a distal end portionand an expandable prosthetic heart valve mounted on the distal endportion, the delivery catheter also having a deflecting segment locatedjust proximal to the prosthetic heart valve and a pusher having a distalsleeve mounted over the deflecting segment; creating an intercostalaccess opening and exposing an apex of a left ventricle; creating apuncture at or near the apex of the left ventricle; inserting anintroducer sheath through the puncture; passing the delivery catheterthrough the introducer sheath and into the left ventricle; using thepusher and sleeve to advance the delivery catheter such that theprosthetic heart valve is positioned in the aortic valve annulus;proximally displacing the pusher and sleeve with respect to thedeflecting segment and then bending the deflecting segment from aproximal handle to facilitate positioning the prosthetic heart valve inthe aortic valve annulus; and then expanding the prosthetic heart valvein the aortic valve annulus for replacing the function of a nativeaortic valve, wherein the step of expanding the prosthetic heart valvein the aortic valve annulus comprises expanding the prosthetic heartvalve within a previously implanted prosthetic heart valve.
 14. Themethod of claim 13, wherein the delivery catheter includes a balloon onits distal end, and the prosthetic heart valve comprises aballoon-expandable stent, the step of expanding including: injectingfluid into the balloon to expand the prosthetic heart valve into contactwith the previously implanted prosthetic heart valve.
 15. The method ofclaim 13, wherein the prosthetic heart valve is expanded into contactwith leaflets of the previously implanted prosthetic heart valve. 16.The method of claim 13, wherein the delivery catheter comprises asteering mechanism for bending the deflecting segment controlled fromthe proximal handle thereof, and further comprising: steering the valvedelivery device from the proximal handle with the steering mechanismwithin the left ventricle to facilitate positioning the prosthetic heartvalve in the aortic valve annulus.
 17. The method of claim 13, furthercomprising placing a purse-string suture generally in a first circledefining a perimeter through the tissue of the left ventricle, andcreating the puncture within the perimeter of the purse-string suture.